1. Field of the Invention
The present invention relates to distributing short messages on a signaling channel for mobile voice and data networks, also known as cell phone networks, and, in particular, to allowing a network provider to customize the routing of short messages to allow distinctive short message services.
2. Description of the Related Art
Networks of communications devices and general-purpose computer systems connected by external communication links are well known and widely used in commerce. The networks often include one or more network devices that facilitate the passage of information between end stations, such as telephones and general purpose computing devices, that originate or receive the information. A network node is a network device or end station connected by the communication links. Information is exchanged between network nodes according to one or more of many well known, new or still developing protocols. In this context, a protocol consists of a set of rules defining how the nodes interact with each other based on information sent over the communication links.
Telephone networks rely on circuit-switched network devices that establish a dedicated line between end stations for the duration of a telephone call. Signals are sent between network nodes to set up a circuit to service a call, to maintain the circuit during the call, and to free up (also called “tear down”) the circuit at the end of the call. Between set up and tear down, voice or other data are transmitted over the circuit.
Mobile telephone networks handle additional signaling to maintain information about the current location of a wireless mobile telephone device and to adapt circuits during a call as the mobile telephone device moves from a cell of coverage by one antenna to a different cell of a different antenna. To accommodate the extra information demands of mobile telephone networks, signaling is accomplished by sending one or more small data packets formatted according to a special signaling protocol over the network. In some networks the signaling data packets are sent over the same communication links as the voice and data; and in some networks the signaling data packets are sent over dedicated signaling data links. A signal transfer point (STP) is a switch that relays messages between network switches and databases, such as databases that contain information about the owner, billing and location of mobile devices. In some networks, at least some signaling data packets are sent over a data packet switched network using one or more gateways between the circuit-switched or signaling links and packet-switched networks and one or more additional protocols.
Mobile telephone service providers have begun to offer a short message service. Short messages use the signaling infrastructure of the telephone network to transmit a short message of text or data between end stations. Short messages are well suited for the small display area of most mobile telephones. For example, current Global System for Mobile communications (GSM) standards for short messages limit the amount of data included in each signaling data packet, also called a control plane data packet, to 140 octets (an octet is eight binary digits called bits), enough for 140 Latin characters. Somewhat longer messages can be accommodated by spreading them over several signaling data packets. Because not all mobile wireless users are available at all times, short messages are stored and sent when the recipient of the message becomes available.
To support the short message service, one or more of a special device called a Short Message Service Center (SMSC) is included in the mobile telephone network. The SMSC receives the short messages over the STP network, stores short messages received from end stations, determines when recipients are available to receive the short messages, and forwards the messages over the STP network when the recipients of the messages become available. Multiple SMSCs are employed to provide backup for each other. An SMSC is a sophisticated and expensive device, capable of storing and processing thousands of messages per second. Mobile telephone service providers (hereinafter called providers) typically pay a license fee to vendors of the SMSCs based on the maximum number of messages per second handled by a SMSC. The providers recoup their licensing expenses by charging users a small per message or flat fee to communicate with short messages.
The short message service has become exceedingly popular among mobile phone users. Large sporadic spikes in short message traffic occur as mobile phone users react to circumstances that affect them, such as large public events, school closings, and news events. Some content broadcasters generate revenue by inducing short message traffic and taking a percentage of the short message billings that result. For example, some contests accept entries by short messages. An important example of short message traffic induced by broadcasters is viewer interaction tabulated by broadcasters, such as in response to polling questions or to vote on the performance of one or more contestants.
The increased use of short message traffic causes a dilemma for mobile service providers when the short message traffic is exceedingly heavy for a short period of time. For example, audience response and voting traffic can involve millions of messages in a few seconds in response to events that are days apart. To handle such peak traffic, the service providers need SMSC licenses of hundreds of thousands of short messages per second that are very expensive. Yet such licenses are not cost effective because such peaks are widely separated in time, and the high capacity is excessive for the intervening periods of time.
A recent approach is to use lower cost devices than STP and SMSC to handle some signaling and short message traffic. For example, a packet-switched network (PSN), such as networks using the Internet Protocol (IP) are used to send some signaling data packets and short messages, thus offloading these data packets from more expensive STP devices. Special protocols for sending signaling data packets over IP have been developed, including the Universal Computer Protocol (UCP) and the Short Message Peer-to-Peer (SMPP) protocol. UCP is described at the time of this writing in “Short Message Service Centre 4.6 EMI-UCP Interface Specification,” CMG Wireless Data Solutions, London, April 2003, the entire contents of which are hereby incorporated by reference as if fully set forth herein. SMPP is described at the time of this writing in “Short Message Peer-to-Peer Protocol Specification, Version 5.0,” SMS Forum, Northgrove Limited, Dublin, 2003, the entire contents of which are hereby incorporated by reference as if fully set forth herein. A gateway device translates between STP signals and UCP or SMPP in IP data packets. For example, IP Transfer Point (ITP) switches, available from Cisco Systems of San Jose, California serve as a gateway between STP nodes and PSN nodes. PSN routers and switches are widely used in public and private networks, and can often be obtained and operated more cheaply than STP devices. Many approaches that use a PSN for some or all short message traffic, still utilize one or more SMSCs to store and forward all short message traffic.
In another recent approach, some short message traffic is diverted from the one or more SMSCs. For example, voting traffic is destined for one or more vote-counting processes executing on one or more host computers connected to a network. The recipient of these messages is fundamentally different from another mobile user. For example, the vote-counting process is effectively always available for the time when short messages to be counted are valid; so, the store and forwarding capability of the SMSC is not needed. Thus, in some recent approaches, short message traffic addressed to a vote-counting process is diverted by one or more network devices from any SMSC and instead forwarded directly to the vote-counting process. Since ITP switches are configurable, such diversion of traffic from SMSCs is done by configuring ITP switches to direct such traffic to the vote-counting processes. Gateway suppliers, such as the ITP supplier, configure these devices to perform such diversion.
In some approaches, the gateway devices are configured to attempt immediate delivery for short messages addressed to another mobile device, because many times the recipient device is available. Only if the recipient is unavailable, is the short message sent on to the SMSC to engage the store and forward capability of the SMSC.
While suitable for many purposes, the recent approach of configuring PSN gateway switches to divert short message traffic from SMSCs has some deficiencies. For example, the target of the diverted traffic may change over time or more targets for diverted traffic may be added over time. The configured gateway devices are then incompatible with the service the provider can offer in commerce. The service provider then contracts with the vendor of the gateway devices to develop new configuration data for the gateway devices and waits for the vendor to deliver the configuration data or new devices. With many different service providers vying for the vendors' attention, the delays between the design of the desired service and the delivery of the configured device may be unacceptably long.
As another example, the type of mobile to mobile short message traffic for which immediate delivery is attempted may vary from one provider to another. A provider who spans several time zones may wish to attempt immediate delivery only for mobile users in the same or adjacent home time zones. Another provider, with a smaller service area, may attempt immediate delivery for all short messages. Other providers may have different criteria for attempting immediate delivery, such as the current location of one or more mobile users, rather than their home locations.
In other examples, a short message service provider may want to block short message traffic from a blacklist of troublesome mobile users, allow short message traffic only from a “whitelist” of paying mobile users, and divert some short message traffic to government authorities during the effective dates of a legal wire-tap order.
Other desirable or competitive short message services may not be predictable when gateway devices are delivered to service providers. The providers are likely to want changes in short message services to meet changing customer demands and interests. A slow response to mobile user demands for improvements and other changes in short message service may lead to an exodus of such users from the provider. Thus, providers of short message services are hindered by needing vendor involvement in accommodating changes to the short message services they provide.
Based on the foregoing, there is a clear need for techniques to configure gateway devices for processing short messages that do not suffer the deficiencies of prior art approaches. In particular, there is a need for techniques that allow short message service providers to configure short message gateway devices without involvement by vendors of the gateway devices.
The past approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not to be considered prior art to the claims in this application merely due to the presence of these approaches in this background section.